HUNDREDS of illegal migrants have been accused of taking advantage of traffic chaos in the Channel Tunnel to try and get into Britain from France.

Riot police were called to deal with disturbances in the Calais area as truckers fought to stop stowaways getting on board their vehicles.

It follows serious problems with overhead power cables on Monday which led to a Eurotunnel car shuttle grinding to a halt 7.5 miles out of the UK.

Some 400 passengers had to get out and walk, as numerous trains, including high-speed Eurostar services from London to Paris and Brussels were cancelled or delayed.

As the transport problems continued today, migrants camped out in the French port tried to make a break for freedom.

"Lorries are backing up for up to three kilometres leading up to the tunnel, and migrants are swarming over the vehicles," said a Calais police spokesman.

"Drivers are having to get out to try and clear the migrants, and to protect their loads, so the situation is becoming very fraught.

"Police officers are on the scene trying to deal with the situation. Some trucks are surrounded by up to a dozen migrants, and there are hundreds of them in the area.

"They get into the back of the lorries or else climb on to the chassis."

It follows the bulldozing of four illegal camps in Calais - a hard-line measure which left around 600 mainly young men hanging around the town.

They are all facing arrest, or dispersal around France, meaning many are desperate to get to Britain as soon as possible.

Traffic chaos led to people being evacuated in the Channel Tunnel [ITV]

Lorries are backing up for up to three kilometres leading up to the tunnel, and migrants are swarming over the vehicles

Calais police spokesman

There they will claim asylum, or else disappear into the black economy.

Following the last bulldozing of a camp near the ferry port last week, police said they were fighting a 'losing battle' to keep the migrants out of Calais.

Those taken into police custody had their personal details recorded, and were then offered advice about how to claim asylum in France.

"The vast majority said they wanted to get to Britain, and in these circumstances there was very little else we can do," said a senior officer involved in the clear-out.

"Most of those apprehended were released and allowed to get on their ways.

"Many destroy their identify papers so we don't even know who they are or where they come from."

A spokesman for Eurotunnel said work on fallen power cables was 'ongoing', meaning continued delays.

The French have insisted there will be no repeat of the Sangatte Red Cross refugee centre which acted as magnet for thousands of illegal migrants near Calais before being shut down in 2002.

Charity workers helping refugees from wars in Syria and Afghanistan have reacted with outrage to the clear-outs, blaming them on a shift to the far-right in French politics.

Most of the migrants play a nightly game of cat and mouse with the police and border officials as they try to reach Britain in the back of lorries, but daytime attempts to get on board are now more frequent.

Calais Mayor Natacha Bouchart has long argued that Britain's 'generous welfare system' is the real cause of the migrant crisis in her town.